A backslash is an escape character in Python. It is used to represent characters that do not normally have a visual respresentation (or those that you can't type using a standard keyboard). For example, '\n' is the new line, '\b' is backspace, and u'\u00c6' is Æ. Since the backslash is used in this way, the literal backslash character needs to be represented as two backslashes. See here for more info.